1. Field of the Invention:
The present invention relates to an electronic endoscope device that can observe stereoscopically a shooting object.
2. Related Art Statement:
Recently, various types of electronic endoscope shooting means of solid-state image sensors such as chargecoupled devices (CCD) have been proposed.
Such an electronic endoscope has a resolution higher than that of the fiberscope, facilitating storing or regenerating of images. In addition, there are other advantages such as easy expansion of image and easy processing of comparing to images.
In regard to early detection of cancer, etc., it is often important to identify fine irregularities on a surface. With a conventional electronic endoscope, however, displayed image was so planar that fine ruggedness could not be identified satisfactorily.
Japan Utility Model Application Publication No. 25360/1973 discloses a stereoscopic endoscope using an image guide fiber. With this example known in the prior art, a pair of image guide fibers are required for the right and left eyes, respectively, resulting in a disadvantage that the diameter of the guide fiber becomes large in the entire length of an inserted part.
In addition, Japan Unexamined Patent Publication No. 80221/1986 discloses a technology for stereoscopic vision, in which a stereoscopically visible image is obtained by means of a pair of image inversion prisms and a pair of electronic shutters and then a stereoscopic view is provided by means of a lens which is selectively controlled in synchronization with the electronic shutters. With this example of related technology, however, an optical path to an image sensor element becomes longer, requiring a longer hard tip part of the inserting part of an endoscope, which gives pain to a patient when the inserting part is inserted as a disadvantage of this system.